Meeting Abstract

90.3  Monday, Jan. 6 14:00  Oxidative stress in red swap crayfish Procanmbarus clarkii exposed to acute hyperosmotic conditions BOLLFRASS, K.T.*; GREEN, C.C.; Louisiana State Univ. Agricultural Center; Louisiana State Univ. Agricultural Center kbollf1@lsu.edu

The red swamp crayfish Procambarus clarkii are commercially important in the gulf coast region of the United States of America and China, and are ecologically important elsewhere as an invasive species. Southern Louisiana is experiencing coastal land loss at a rapid rate, causing saltwater intrusion and threatening commercial production in some areas. Red swamp crayfish are tolerant of moderate salinity but maintaining homeostasis under environmental stress increases basal metabolism and oxidative stress. Currently little is understood about antioxidant defense and oxidative stress in crayfish related to increased salinity. In this study, red swamp crayfish were acutely transferred from salinities of 0 psu to 5, 10, or 20 psu water. Tissues and hemolymph were sampled (n=6) at 0, 12, 24, 72, and 120 h after transfer. Biochemical assays were performed to quantify antioxidant enzymes, lipid peroxidation, and hemolymph chloride ions. Sodium and potassium ions were quantified with flame spectrophotometry. Real time qPCR was used to quantify the expression of prophenoloxidase and superoxide dismutase genes. Total osmolarity, sodium, potassium, and chloride significantly increased in crayfish hemolymph 24 h after exposure to hyperosmotic conditions. Lipid peroxidation was significantly higher in crayfish heptaopancreas tissue 72 h after exposure. Superoxide dismutase was significantly lower in crayfish gills 72 h after exposure. These findings explore the biocemical and molecular underpinnings of oxidative stress from acute hyperosmotic stress.